1. Field of the Invention
The present invention relates to a disk apparatus for carrying out a reproduction, recording and erasing of information registered in a disk, for example, a DVD player, and more particularly to a disk apparatus for moving a tray forward and backward smoothly by preventing a so-called avalanche phenomenon of a disk and without damaging the disk.
2. Description of the Related Art
The examples of the related art DVD players include an example shown in FIGS. 6, 7A, and 7B. In this example, a rectangular box type case 1 is formed by a top plate 1a, a bottom plate 1b and a front plate 1c, and provided at one front side corner portion with an apparatus body 2. Around the apparatus body 2 in the case 1, a substantially L-shaped AV printed board 3 in plan and a rectangular main printed board 4 are provided.
The apparatus body 2 has a main chassis 8 supporting a tray 17 adapted to place a disk D thereon so that the tray can be moved forward a and backward b, and a drive chassis 13 which is supported on the main chassis 8 so that the drive chassis can be moved up c and down d around a pivot 9, and which is mounted with a spindle motor 12 provided with an optical pickup 10 and a turntable 11. A cam shaft 14 projecting from a front surface of the drive chassis 13 is fitted in a cam hole 15a of a cam slider 15, and the cam slider 15 is provided on the main chassis 8 so that the cam slider can be slid in the lateral directions e, f which orthogonally cross the longitudinal directions a, b. When the cam slider 15 is slid in the leftward direction e (or rightward direction f), the drive chassis 13 is moved in the vertical directions c, d. A magnet-carrying disk holder 17 opposed to the turntable 11 is set on lateral beam 18 provided between both side walls 8a of the main chassis 8 so that the disk holder can be moved up and down within a predetermined range. Referring to FIG. 1, a reference numeral 19 denotes a disk storage recess formed in a central portion of the tray 7, and 20 a floatation preventing members extending from both side walls 8a of the main chassis 8 to positions above both side edge recesses 7a of the tray 7.
The principle of the actions of this structure will be described. The solid lines in FIG. 6, and FIG. 7A show a playing mode. The disc D is rotated at a high speed by the spindle motor 12 via the turntable 11, and the information recorded in the disk D is read by the optical pickup 10, an image being reproduced on the monitor.
When an unloading signal is inputted from the playing mode, the cam slider 15 is slid leftward e (or rightward f) as shown in FIG. 7B to cause the driving chassis 13 to be moved down d. As a result, after the disk D is transferred from the turntable 11 to the tray 7, the tray 7 is advanced forward a through a disk takeout port 21 of the front plate 1c. The disk D is then taken out from the tray 7, and a new disk D is placed on the tray 7.
When a loading signal is then inputted, the tray is moved back b as shown in FIG. 7A to cause the tray 7 to be moved back b and stored in the interior of the case 1. The cam slider 15 is then slid rightward f (or leftward e) to move the driving chassis upward c and hold the disk D on the tray between the turntable 11 and disk holder 17.
According to the structure, when the power source is turned off on the basis of the unloading signal as shown by solid lines in FIG. 8 with the tray 7 in an forwardly a advanced state, the drive chassis 13 is stopped in a downwardly d moved state. When the tray 7 is forcibly pushed by fingers in the backward b direction and thereby return the tray 7 into the interior of the case 1, the disk D on the tray 7 is held between the turntable 11 and disk holder 17 with the turntable 11 in a lowered state as shown by solid lines in FIG. 8.
When the case is inclined as shown in phantom as shown in FIG. 8, so as to, for example, transport the case 1 to another place with the disk D not held as in the above-described state, the disk D stored in the disk storage recess 19 is disengaged therefrom in the backward b direction. As a result, the disk D is disengaged from a proper position to the extent that a rear half portion of the disk D projects from the tray 7 as shown in a position shown by . . . , and a so-called avalanche phenomenon occurs.
When the power source is turned on in this condition to cause the tray 7 to be moved forward a on the basis of an unloading signal, there is the possibility that the disk D is left in a rear position and falls into the case 1, and that the disk D is held between the forwardly a moving tray 7 and lateral beam 18.
As examples of the related techniques solving these problems, there are techniques disclosed in JP-A-6-251479. In the techniques, a hook is projected from a circumferential edge of a disk storage recess 19 of a tray 7 so as to thereby prevent by inclining a case 1 a disc D from being disengaged from the disk storage recess 19.